From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Product specification sheet for High Tension Electrostatic Voltmeters.
| Identifier | ExFiles\Box 53\1\ Scan156 | |
| Date | 1st February 1907 | |
| Supersedes Sheet 15/1504. Sheet 15. 2107. EVERETT EDGCUMBE & CO LTD MANUFACTURERS OF ELECTRICAL MEASURING INSTRUMENTS OF EVERY DESCRIPTION. Colindale Works, HENDON, N.W. 9. Trade E E C Mark. Registered. 117, Victoria Street, WESTMINSTER, S.W. 1. 501000 Fig. 1. Portable Pattern. Fig. 2. Switchboard Pattern. HIGH TENSION ELECTROSTATIC VOLTMETERS. (For H.T. Electrostatic Leakage Indicators, see Sheet 44.) These Electrostatic Voltmeters consist essentially of a condenser in which one plate, or set of plates, is fixed and the other moveable. A pointer is attached to the latter and indicates the voltage of the system to which the instrument is connected. The Everett-Edgcumbe form of Electrostatic Voltmeter is designed with a large factor of safety and the importance of this will be fully recognised in view of the high pressures dealt with, and the abnormal rises in pressure which occur in practice, due to the sudden opening of circuits, inductive surges on transmission lines, etc. (see Sheet L). They possess the advantage that they absorb no energy, have no temperature error, and are independent of variations in wave-form or frequency. They are also unaffected by external magnetic or electrostatic fields. Patterns. These instruments are supplied in the Switchboard Pattern in two sizes, viz., with 8in. dial (4 1/2in. scale), or with 12in. dial (7 1/2in. scale). They are also supplied in the Portable Pattern in one size having a 7 1/2in. scale. Finish. The standard finish of the switchboard pattern (Fig. 2) is bright black stove enamelled case, the front being dull black with raised portions heavily plated in nickel or copper or bright black, as preferred. When ordering, the finish should be stated as “black and nickel,” “black and copper,” or “all black.” | ||